1. Field:
This disclosure is concerned generally with medically useful needle assemblies and is especially concerned with a venipuncture needle assembly used in conjunction with blood collection equipment.
2. Prior Art:
Various needle assemblies consisting of sterile hypodermic or venipuncture needles enclosed in needle protectors are well known and the subject of many patents. One such recent patent is described in U.S. Pat. No. 4,435,177, the teachings of which are incorporated herein by reference to it.
Very generally, the needle protector portion of medically useful needle assemblies are of at least two types. In one type, the bevel tip of a needle is embedded in a relatively soft material such as rubber or cork stopper as shown in U.S. Pat. Nos. 2,688,963; 2,667,163; 2,688,964; and 3,416,657. As pointed out in U.S. Pat. No. 4,435,177, there are known disadvantages to this type of protector. In another type of needle protector, the needle is enclosed in a relatively rigid (hard) plastic material. A needle of this type is shown in U.S. Pat. No. 4,435,177 and in many of the other patents cited therein. Although the more rigid needle protectors are intended to protect the needle (especially its fine-edged bevel tip) after final assembly and, to a certain extent during storage, the hard protectors often damage the bevel tip of the needle during assembly steps or after or while the protector is removed. Even a slight contact of the very sharp bevel edge of the needle against a hard protector can cause damage to the needle tip. This damage may cause unnecessary pain and trauma to a patient. This is especially true for venipuncture needle assemblies where relatively large gauge needles are used.
As can be appreciated, the final choice of a relatively hard vs. a relatively soft needle protector typically involves a trade off of benefits and detriments depending on the intended use of the needle assembly. It has now been found that the respective advantages of both hard and soft needle protectors can be obtained in a single needle assembly which is relatively easy and inexpensive to manufacture. Details of our discovery are described below.